Linq查詢以獲取過濾后的主集合以及該集合中結果的每個列表

Question

這些是我的課程：

public class Restaurant
{
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }
    public City City { get; set; }
    public List<Meal> Meals { get; set; }
}

public class Meal
{
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime Date { get; set; }
    public int Price { get; set; }
    public int Number { get; set; }
    public int Kind { get; set; }
}

現在我想創建一個查詢，為我提供城市中的餐廳列表以及今天的用餐日期，因此我開始是這樣的：

return db.Restaurants.Where(rest => rest.City.Name == city).Include(rest => rest.Meals);

但是我不確定如何與這部分聯系：

.Where(meal => meal.Date == DateTime.Today)

所以我會得到想要的結果。 那么怎么可能呢？ 謝謝

編輯：

我的結果：

        return db.Restaurants
                 .Include(rest => rest.Meals)
                 .Where(rest => rest.City.Name == city)
                 .AsEnumerable()
                 .Select(r => new Restaurant()
                     {
                         City = r.City,
                         Id = r.Id,
                         Name = r.Name,
                         Meals = r.Meals.Where(meal => meal.Date == DateTime.Today).ToList()
                     });

Answer 1

這應該在視圖模型（或Dto）層中完成，首先，定義視圖模型：

public class RestaurantVM
{
    public int Id { get; set; }
    public string Name { get; set; }
    public City City { get; set; }
    public List<MealVM> Meals { get; set; }
}

public class MealVM
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime Date { get; set; }
    public int Price { get; set; }
    public int Number { get; set; }
    public int Kind { get; set; }
}

然后，您可以像下面這樣編寫LINQ：

var restaurantVMs = db.Restaurants
                  .Include(rest => rest.Meals)
                  .Where(rest => rest.City.Name == city)
                  .AsEnumerable()
                  .Select(r => new RestaurantVM(){
                        Id = r.Id,
                        Name = r.Name,
                        City = r.City,
                        Meals = r.Meals.Where(meal => meal.Date == DateTime.Today)
                                       .Select(m => new MealVM(){
                                            ...
                                        }).ToList()
                    }).Where(r => r.Meals.Count > 0);